1. Field of the Invention
The present invention relates to an activation control apparatus of an occupant safety system for controlling activation of the occupant safety system which provides protection for vehicle occupants in the event of a vehicle collision.
2. Related Background Art
The vehicles now available are often equipped with an airbag system for providing the protection for vehicle occupants in the event of a vehicle collision. This airbag system has a sensor for detecting impact upon collision of the vehicle and is activated based on the impact detected by this sensor.
Incidentally, types of vehicle collision include a variety of crash types such as a frontal crash, an offset crash, and so on. In order to be able to detect the collision of the vehicle in the event of any type of crash, there exist the airbag systems constructed in such structure that sensors are located at plural positions in the vehicle and that the airbag system is activated based on detection of the collision of the vehicle by the plurality of sensors. (Reference is made to Japanese Patent Application Laid-Open No. 5-38998.)
In the airbag systems described above, the vehicle collision was able to be detected in the event of any type of collision, but it was difficult to activate the airbag system with accuracy in accordance with either of the crash types, because the crash types were not discriminated from each other.
An object of the present invention is to provide an activation control apparatus of an occupant safety system that can discriminate the crash types of the vehicle from each other with accuracy and that can activate the occupant safety system with accuracy in accordance with either of the crash types.
An activation control apparatus of an occupant safety system according to the present invention is an apparatus for controlling activation of the occupant safety system mounted on a vehicle in the event of the vehicle colliding with an obstacle, the apparatus comprising a plurality of impact detecting means mounted at mutually different positions in a front part of the vehicle, collision type identifying means for identifying a type of collision of the vehicle, based on values detected by the plurality of impact detecting means, and activation control means for controlling the activation of the vehicle safety system, based on a type of collision identified by the collision type identifying means. The front part of the vehicle herein means the vicinity of the bumper at the front end of the vehicle, the vicinity of the front ends of the front side members, the areas on the front side members, the area on the dash panel, and so on.
Since the activation control apparatus of the occupant safety system can identify the type of collision of the vehicle by the collision type identifying means, the activation control means can activate the occupant safety system more accurately.
The activation control apparatus of the occupant safety system is also characterized in that the plurality of impact detecting means comprise first impact detecting means mounted in a left part of the vehicle and second impact detecting means mounted in a right part of the vehicle and in that if after the collision of the vehicle there is a time difference between rises of values detected by the first impact detecting means and by the second impact detecting means the collision type identifying means identifies the collision as an oblique crash. Here the left part of the vehicle and the right part of the vehicle mean the vicinity of the left and right ends of the bumper, the vicinity of the left and right front side members, the areas on the left and right front side members, the vicinity of the left and right ends of the dash panel, and so on.
The activation control apparatus of the occupant safety system can identify the collision of the vehicle as an oblique crash by the collision type identifying means. Namely, since in the event of the oblique crash relatively small impact acts on the bumper at the front end of the vehicle to cause a time difference between rises of the values detected by the first impact detecting means and by the second impact detecting means, the collision can be identified as an oblique crash.
The activation control apparatus of the occupant safety system is also characterized in that the plurality of impact detecting means comprise first impact detecting means mounted in a left part of the vehicle and second impact detecting means mounted in a right part of the vehicle and in that if after the collision of the vehicle there is a time difference between rises of values detected by the first impact detecting means and by the second impact detecting means and if a difference is large between magnitudes of the values detected by the first impact detecting means and by the second impact detecting means the collision type identifying means identifies the collision as an offset crash.
The activation control apparatus of the occupant safety system can identify the collision of the vehicle as an offset crash by the collision type identifying means. Namely, since in the event of the offset crash either one of the first impact detecting means and the second impact detecting means detects greater impact, the collision can be identified as an offset crash.
Another activation control apparatus of an occupant safety system is an apparatus for controlling activation of the occupant safety system mounted on a vehicle in the event of the vehicle colliding with an obstacle, the apparatus comprising first impact detecting means mounted in a left front part of the vehicle, second impact detecting means mounted in a right front part of the vehicle, likelihood computing means for classifying collision of the vehicle under a frontal crash, an offset crash, and an oblique crash, based on values detected by the first impact detecting means and by the second impact detecting means, and computing a likelihood of the collision classified, and activation control means for controlling the activation of the occupant safety system, based on the likelihood computed by the likelihood computing means.
In the activation control apparatus of the occupant safety system the likelihood computing means classifies the collision of the vehicle under the frontal crash, the offset crash, and the oblique crash, based on the values detected by the first impact detecting means and by the second impact detecting means, and computes the likelihood of the collision classified. Therefore, the activation control apparatus can determine the type of collision of the vehicle accurately and activate the occupant safety system with accuracy.
The activation control apparatus of the occupant safety system is also characterized in that when the likelihood computing means classifies the collision as an oblique crash and computes the likelihood of the oblique crash, the activation control means controls the activation of the occupant safety system with reference to an oblique crash threshold corresponding to the likelihood of the oblique crash.
The activation control apparatus of the occupant safety system is also characterized in that when the likelihood computing means classifies the collision as an offset crash and computes the likelihood of the offset crash, the activation control means controls the activation of the occupant safety system with reference to an offset crash threshold corresponding to the likelihood of the offset crash.
The activation control apparatus of the occupant safety system is also characterized in that when the likelihood computing means classifies the collision as an ODB crash and computes the likelihood of the ODB crash, the activation control means controls the activation of the occupant safety system with reference to an ODB crash threshold corresponding to the likelihood of the ODB crash.
The activation control apparatus of the occupant safety system is also characterized in that the ODB crash threshold is set as follows; in a small deceleration range from occurrence of the collision a threshold corresponding to a strong-likelihood ODB crash is lower than a threshold corresponding to a small-likelihood ODB crash and in a large deceleration range from occurrence of the collision a threshold corresponding to the strong-likelihood ODB crash is higher than a threshold corresponding to the small-likelihood ODB crash.
The activation control apparatus of the occupant safety system is also characterized in that when the likelihood computing means classifies the collision as a soft crash and computes the likelihood of the soft crash, the activation control means controls the activation of the occupant safety system with reference to a soft crash threshold corresponding to the likelihood of the soft crash.
The activation control apparatus of the occupant safety system is also characterized in that in a small deceleration range from occurrence of the collision a soft crash threshold corresponding to a strong-likelihood soft crash is lower than a soft crash threshold corresponding to a small-likelihood soft crash and in a large deceleration range from occurrence of the collision a soft crash threshold corresponding to the strong-likelihood soft crash is higher than a soft crash threshold corresponding to the small-likelihood soft crash.
In the activation control apparatus of the occupant safety system the likelihood computing means classifies the collision under the oblique crash, the offset crash, the ODB crash, and the soft crash and computes the likelihood of the collision classified. The activation control means controls the activation of the occupant safety system with reference to the threshold corresponding to the likelihood of the collision classified. The apparatus can activate the occupant safety system at accurate timing accordingly.
The activation control apparatus of the occupant safety system is also characterized in that the likelihood computing means classifies the collision of the vehicle under a frontal crash, an offset crash, and an oblique crash, based on a ratio of the values detected by the first impact detecting means and by the second impact detecting means, and computes a likelihood of the collision classified.
The activation control apparatus of the occupant safety system is also characterized in that the likelihood computing means classifies the collision of the vehicle as a frontal crash when the ratio of the values is large, classifies the collision as an oblique collision when the ratio of the values is small, or classifies the collision of the vehicle as an offset crash when the ratio of the values is intermediate.
In the activation control apparatus of the occupant safety system the likelihood computing means classifies the collision of the vehicle under the frontal crash, the offset crash, and the oblique crash, based on the ratio of the values detected by the first impact detecting means and by the second impact detecting means and, therefore, the collision can be classified under the crash types with accuracy.
The activation control apparatus of the occupant safety system is also characterized in that the likelihood computing means classifies the collision of the vehicle under an ODB crash and an ORB crash, based on an initial deviation between the values detected by the first impact detecting means and by the second impact detecting means, and computes a likelihood of the ODB crash, based on the initial deviation, when the collision of the vehicle is classified as an ODB crash.
The activation control apparatus of the occupant safety system is also characterized in that the likelihood computing means determines that the likelihood of the ODB crash is strong when the initial deviation is large, or the likelihood computing means determines that the likelihood of the ODB crash is small when the initial deviation is small.
In the activation control apparatus of the occupant safety system the likelihood computing means classifies the collision of the vehicle under the ODB crash and the ORB crash and computes the likelihood of the ODB crash, based on the initial deviation between the values detected by the first impact detecting means and by the second impact detecting means, and, therefore, it can classify the collision under the crash types with accuracy and compute the accurate likelihood thereof.
The activation control apparatus of the occupant safety system is also characterized in that the likelihood computing means determines whether the collision of the vehicle is the ODB crash, based on the magnitude of the difference between the values detected by the first impact detecting means and by the second impact detecting means, and computes a likelihood of the ODB crash, based on the magnitude of the difference between the values detected, when it is determined that the collision of the vehicle is the ODB crash.
The activation control apparatus of the occupant safety system is also characterized in that the likelihood computing means determines that the likelihood of the ODB crash is strong if the magnitude of the difference between the values detected is large, or determines that the likelihood of the ODB crash is small if the initial deviation is small.
In the activation control apparatus of the occupant safety system the likelihood computing means determines whether the collision of the vehicle is the ODB crash, based on the magnitude of the difference between the values detected by the first impact detecting means and by the second impact detecting means, and computes the likelihood of the ODB crash and, therefore, it can classify the collision under the crash types with accuracy and compute the accurate likelihood thereof.
The activation control apparatus of the occupant safety system is also characterized in that the activation control apparatus comprises impact measuring means placed in the vehicle, the likelihood computing means determines whether the collision of the vehicle is a soft crash, based on a state of unevenness of a temporal change waveform of a measurement measured by the impact measuring means, and the likelihood computing means computes a likelihood of the soft crash, based on the unevenness of the temporal change waveform of the measurement when it is determined that the collision of the vehicle is the soft crash.
The activation control apparatus of the occupant safety system is also characterized in that when the unevenness of the temporal change waveform of the measurement is large, the likelihood computing means determines that the likelihood of the soft crash is strong and in that when the unevenness of the temporal change waveform of the measurement is small, the likelihood computing means determines that the likelihood of the soft crash is small.
In the activation control apparatus of the occupant safety system the likelihood computing means determines whether the collision of the vehicle is the soft crash, based on the state of unevenness of the temporal change waveform of the measurement measured by the impact detecting means, and determines the likelihood of the soft crash, also based thereon, and, therefore, it can determine the type of the collision with accuracy and compute the accurate likelihood thereof.
Another activation control apparatus of an occupant safety system is an apparatus for controlling activation of the occupant safety system mounted in a vehicle in the event of the vehicle colliding with an obstacle, the apparatus comprising impact measuring means placed in the vehicle, soft crash determining means for determining whether the collision of the vehicle is a soft crash, based on a state of unevenness of a temporal change waveform of a measurement measured by the impact measuring means, and activation control means for controlling the activation of the occupant safety system, based on a soft crash activation determination map, when the soft crash determining means determines that the collision is the soft crash.
In the activation control apparatus of the occupant safety system the soft crash determining means determines whether the collision of the vehicle is the soft crash, based on the state of unevenness of the temporal change waveform of the measurement measured by the impact measuring means. Therefore, the apparatus can accurately determine whether the collision is the soft crash and can activate the occupant safety system with accuracy.
The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only and are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.